Absorber



J. A. CAMPBELL ABSORBER Filed July 19' 1926 Jly .14, 1931.

if lo@ Patented" July 14, 19314 UNITED STATES vPA'rEN'r o1-Fics JULIAN A. GAMPBELL, F LONG BEACH, CALIFORNIA ABsonBEB Y AApplication led July 19, 1926. Serial 17o. 123,417.

This invention hasA to do with devices ofk the general character and type that are variously known as absorbers or bubble towers; their function being to intimately distribute and admix gas or vapor with a liquid so as to get intimate finely dividedcontact between the gas and liquid. Sometimes these devices are used for the purpose of absorbing condensible vapors'from gases; at other times such devices are used to load a gas or vapor with substances that they may pick up from the liquid by reason of intimate contact therewith. Thus although'I call the present device an absorber, and its principal use is for absorbing vapors from gases, 1t will be understood that the invention is not thereby to be limited to such'l use.

The device illustrated in the accompanying drawings and described hereinafter is similar in general structure to the devices explained in my co-pending applications Serial Number 46,974, filed July 30, 1925, entitled Absorber; and Serial Number 79,073, filed January 4, 1926, entitled Absorber. The first mentioned application 1s directed particularly to the structural features of such an absorber; and although-similar structural features (for supporting several superimposed floors, etc.,) are lshown 1n the present application, it W1ll be understoodl that the invention subject matter of this present application is not to be limited thereby. The second mentioned co-pending application is directed in subject matter to an absorber made u of a plurality `of Xsuperposed spaced perfbrated floors with overflow pans arranged above each floor, the overflow from the pans flowing down and being spread'out over the next floor below. The subject matter of the present application is similar to this in some respects; but the characteristic improvement embodied in the present invention, the provisionv of double or multiple perforated floors for the purposes to be hereinafter described, although preferably used in conjunction with said arrangement of overflow pans, is not necessarily to be limited in its broader aspect to such combination.

using a series of perforated floors, each lloor being in the form of a single perforated plate and the oil on a given floor being delivered to it from an overflow pan associated with the floor next above, it is found that a por- 65 tion of the liquid does not come into intimate contact with the gas. This'is for the reason that there is necessarily an appreciable distance between adjacent plate orifices and the streams of bubbles passing upwardly fr om these orifices are accordingly somewhat widely spaced'apart so the liquid between these streams is not immediately effected by the gas flow.

It is an object of the present invention to overcome this difficulty, that is, to insure intimate contact between the gas and practically all the liquid as they come into contact at each floor. Generally, I accomplish'this by forcing the oil and gas together through floor apertures, in contradistinction to the old method of merely passing the gas through the apertures and into the body of liquid thereabove.

This is done by making up each floor of two or more vertically spaced and perforated plates. Gas occupies the full cross-section of the shell below the lowermost plate and oil is admitted to the space between plates from the floor next above. The gas is forced u 90 wardly through relatively small orilices 1n the lower plate, its velocity thereby being increased -appreciably, and the rapid flow of this gas into the body of oil or other liquid above the lowermost plate whips the 35 liquid into a fro'th consisting of innumerable oil film bubbles. These bubbles, that is, vesicles of oil containing as, are carried upwardly through the ori ces in the superimposed plate or plates and in passing through these orifices the bubbles are broken up and the gas Within them brought into intimate contact with the oil released from the films of the broken bubbles and with any unfrothed Ioil, such unfrothed oil being 95 forced with the bubbles through the upper plate orifices.

Furthermore, the high velocity of the as, by reason of being suddenly constricte in its low from the full-and free cross-section lo of the shell to the very vlimited aggregate lareaof the orifices, has an atomizing effect the shell but at a point above the floor.

Should more than one apertured plate be provided beneath the uppermost plate, the action through the additional plate or plates is practically the same as through the uppermost late, that is, such plates function to lconstrict the bubbles suddenly, breaking them up and bringing the gas into intimate contact with the broken films.

Of course, as the bubbles are broken up in passing through the plate orifices, new bubbles are constantly being formed. 'After passing through the additional plates, however, the bubbles do not reach the surface of a free body of liquid so as to burst naturally, until they have passed through the uppermost plate, in other words, the space Abetween plates is practically filled with froth. The effect of using additional plates in each floor multiplies the beneficial effects gained by the use of one such plate lbut in- Fcreases the pressure drop through the apparatus. This, alone, is the limiting factor in their use.

The liquid passes into overiow pans above the uppermost plate and thence drops to the iloor next below, and it will be seen 4that every bit of oil thuspassed has previously been forced upwardly through gaspassing apertures and has therefore been in intimate contact with the gas.

The accompanying drawings illustrate a typical form that the invention may take. In these drawings:

Fig. 1'is a fragmentary vertical central' section of the lower part of a. bubble tower; Fig. 2 is a horizontal section on line 2 2 vof Fig. 1; and

Fig. 3 is a fragmentary enlarged detailed section on line 3-3 of Fig. 2.

Fig. 4 shows a fragment of a tower illustrating a modification.

In the drawings the lower part of a cylindrical shell is shown at 10, and its bottom 11 is preferably made in the form illustrated in Fig. 1, its similar top not being shown. At 10a is an inlet for the rich gas under pressure; and at 10b an outlet for the laden absorbing oil. Above the bottom there may be as many superimposed oors 13 as may be desired. In the structural form herein shown these iioors are supported by vertical supporting columns 15 extending upwardly from the bottom of the shell. The details of these supports need not here be gone into as they are the particular subject matter of the first mentioned co-pending application.

'Each iioor 13, in accordance with my present invention, is made up of a series of vertically s aced plates, two or more in number; an in Figures 2 and 3 I have shown each floor consisting of an upper and a lower plate 20 and 21, these plates preferably being circular and forming a froth chamber 22 between them. It will be understood, however, that this showing of only two plates to each iioor is not limitative on the invention considered in its broader aspects. Chamber 22 is bound 'at its circular edge by aperipheral wall 23 constructed of a channel iron bent to circular shape. The

several floors being supported by columns 15,` they are not supported from the exterior shell 10,'but means are provided` for makinga fluid tight joint between the floors and the exterior shell. In general this fluid tight joint is provided by packing 24 around the edge of each ioor, with a follower ring 25 above the packing. The subject matter of this packing ins, however, fully described in the firstmentioned one of my co-pending applications and need not be described in detail here.

Above each floor, and in Figures 2 and 3 shown as-resting on the upper surface of each floor, is a plurality of overflow pans 26, these pans being relatively iat and shallow, arranged in symmetrical order aboutl the center of the floor, and altogether covering a substantial proportion of the floor area. It is not essential to the invention, however, that the pans rest directly on the uppermost plate of the iioor; in fact, in

certain situations, it is preferable that the pans be spaced vertically above the uppermost plate, as shown in Figure 4 and as will be described at a later Vpoint herein. Preferably the circular edges of these pans may be somewhat sharp, as indicated at 27; a good way of makin these sharp edges being merely to leave e ge 27 raw as it comes from a Hanging machine or a shears. The bottom of each pan has a short depending nipple 28 that extends down through an opening in upper plate 20; this nipple extending at its lower end into a vertical tube 29 that passes through the lower plate 21 and extends on down to the upper plate 2O ofthe next floor below. A sufficiently tight joint is made with the last mentioned plate 20 by having the lower end of tube,

29 telescope around a nipple 30 mounted on that plate 20. Said upper plate 20 has an opening at 31 registering with each nipple 30; and directly below this opening and mounted on the corresponding lower plate 21 there is a spreader cone 32. This cone is preferably not mounted directly on plate 21 but has its lower edge spaced somewhat lll above plate 21 b using spacers 33 around the mounting bo ts 34. f Both plates 20 and 21 are perforated sublstantially throughout their entire extent, as is shown at 35, the lower plate 21 being also perforated under spreader cones 32. The upper plate may or may not be perforated under pans 26, the perforations under the pans resting on that plate being moperative even if lthey are present. Consequently in Fig. 3 the part of plate 20 under pan 26 is shown unperforated. l

A fluid ti ht joint is` maintained between tube 29 and the lower plate 21 through which the tube passes by means of a packing that is compressed between a flange 41 and the under face of plate 21; and any leakage of gas or liquid from the chamber 22 between the plates is further prevented by a nipple 42 that surrounds nipple 28 and the upper end of tube 29 and is tightly clamped between the two plates by bolts 43, which bolts also hold pan 26 down to the floor. The lower edge of nipple 42 may also be welded, as indicated at 44, to bottom plate 21 so as to prevent any fluid from owing under the lower edge of that f nipple. The nipples also perform the funcv tion of accurately spacing the two plates alpart at several spaced points, so as to keep t e two plates, throughout their extents, at

-uniform spacing.

Although it will be readily recognized that the sizes of the plate perforations and their spacings will depend upon thev character of liquid being treated and also upon the amount of gas that is lbeing put through a tower, I may say that in a typical instance the perforations in the lower plate may be about inch diameter, while those in the upper plate may be somewhat larger or about flg inch diameter, the perforations of the bottom plate being on one-inch centers and of the top plate on 3A in ch centers. The top plate is thus iven somewhat greater aggregate area of, gas-passing orifices than is the lower plate; but it must be remembered that in the operation of the device the pressure under the lower plate is lalso somewhat greater than the pressure under the upper plate. Gas is always fed in at the bottom of the absorber shell and passes successively up through the several superposed floors so that at each floor and at each perforated plate. of each floor the gas drops somewhat in pressure. A For the purpose of illustrating introduction of absorbing oil to an uppermost floor,

- a pipe 10c is shown in Fig. l introducing the oil above the highest floor there shown. It will be understood that as many superimposed floors as desired may be used.

In operation the liquid, typically hydrocarbon oil, petroleum or petroleum derivative, is fed in at the top of the tower and,

amount of spreading out over the uppermost'fioor, is -raised into a froth by the lgas fed 1n at the bottom and passing up t rough the perforated floors, until the froth reaches the level of the pan edges. Here the froth, breaking up, liberates liquid oil which flows over the pan edges into the pans and thence down through tubes 29 to the enclosed chamber 22 of the next floor below, bein spread out by cones 32. The fact that t ere are perforations 35 under the cones, with gas consequently passing radially outwardly under the cone edges, also assists in the spread of the liquid over lower plate 21, so that the liquid is spread in a comparatively thin film widely around each cone.

The gas passing up through the lower plate perforations picks up this thin film of oil, forming bubbles, and chamber 22 becomes filled with a frothy mass which is more or less lcompletely in the form of bubbles. This mass of froth is being constantly moved upby the upwardly flowing gas forming new froth below; so that the mass of froth, and with it any unbubbled or unfrothed oil, is carried up to the upper plate20 and forced through the perforations in the upper plate. The speed at which this frothy mass moves upwardl and the velocityat which the froth an the liquid oil is projected through perforations 35 of the upper plate depend, of course, upon the size and number of the perforations and the gas and oil being fed to the and the pressure present at the plates. But in practical operation the conditions are made such that the froth and any free oil is forced up through the upper perforations 35 with some little velocity so that any liquid oil is more or less atomized and becomes intimately admixed with gas that is forced out of any bubble or bubbles too large in size to pass freely through upper perforations. The passage through the upper perforations, therefore, bursts the gas bubbles and re-forms bubbles of substantially uniform size. This action brings the gas into intimate contact with any oil that has not been bubbled at the lower plate, forming above the upper plate a uniform mass largely of froth. As a consequence the gas is brought into very uniform and intimate contact with all the oil which is subsequently passed to the floor next below, with the result that absorption by the oil is very uniform and highly efficient. The bubbles burst naturally, or by contact with the pan edges when they reach the surface of the liquid and the gas is thus freed for action with the oil on the floor next above.

absorber,

It will be understood that this action is below. Under the lowermost floor the discharge tubes 29 will have at their lower ends suitable liquid trap cups 50 to prevent passage of gas upwardly through the lowermost tubes 29. Passage of gas up through the other tubes 29 is prevented by the fact that those tubes normally contain columns of oil.

Although, as I have shown the proportions and arrangements in the drawings, the several plates 20 and 21 are closer together in each Hoor than the spaciiigs between the several floors, it will readily be recognized that these proportional spacings are not a limitation uponthe invention. Typically, in practi-,gal construction the two plates of each floor will be closer together than adjacent floors; and typically the plates of each floor are made into a structural unit. But the structure and arrangement of the absorber as a whole may be looked upon as one embodying a plurality of spaced perforated l plates, alternate spaces between plates being froth chambers and the remaining spaces between plates being chambers in ywhich the froth is broken up and the liquid oil fed downwardly to the next froth chamber below. Or, the perforated plates may be said to function in pairs, without necessarily being structurally associated together in pairs. The plates of each pair enclose the froth chamber; the chambers lbetween pairs are those in which the froth is broken up. Considering the invention in this light, it will be seen that it is not in its broader aspects to be limited by the typical structural details herein explained, although in practical use these structural details may usually be used.v

In Fig. 4 I haveshown afragment of av tower wherein certain variational character-I.

istics are illustrated, the variations consist:`

ing mainly of lthe provision of more than two plates to a floor, the spacing of the overflow pans above Ithe'uppermost plate and the provision of operative apertures in plat-e beneath the pan.

In this figure, suoli parts of the structure' as are like corresponding parts of the previously described structure, are given similar reference numerals, but with the exponent y Floor 13ais made up of uppermost other figures; and it will be understood I' may employ more than three spaced plates in making up each fioor.

Overflow pans 26a, of which only one is hown in Fig. 4, are similar to pansv 26, but are here shown as being spaced vertically above plate 20w by such means, for instance,

most plate is not limited in application to the structure shown in Fig. 4, but may also be embodied in the structure of Figs. 2 and 3, as will be readily understood. It will also be understood that it is not essential to the three or more plates type of floor that the overflow pans be spaced above the uppermost floor, but that in some situations I may rest the pans upon the uppermost plate in the manner illustrated in Figs. 2 and 3.

The assembly of the pans, nipple 28a, tube 29a, spacing nipples 42a, etc., may be similar to that described in'connection with corresponding parts of the other figures.

With the overflow pans spaced above plate 20a., it is preferable that apertures 35a be provided directly beneath the pans, as illustrated. The connection of tube 29a, with the floor below, is the same as previously described in connection with tube 29.

The operation of the variational structure shown in Fig. 4 is generally similar to that described in connection with the other figures, except that the froth from chamber 22a is forced through the apertures in plate 51 before it passes through chamber52 and the apertures in plate 20a, 'insuring a thorough admixture of the gas and oil.

I claim: i

1. In an absorption tower or the like, a. bubbling floor embodying .two vertically spaced perforated plates enclosing between.

them. al froth chamber, means for feeding liquidjintofsaidplate enclosed chamber in- .dependentlyof the perforations in the upper gplate', meansfor'supplying` gas under 'pressure' under the lower'plate', and means .Y

forremoving froth from a' point abovethe upper plate.. Inan absorption toweror theglike, a

spaced perforated plates enelosingbetween :tlieirif'a froth chamber, means for feeding liquid into saidplate enclosed chamber independently of the perforations inthe up- '.'per.plate, means for supplying gas under pressure under the lower plate, and means for; removing froth from a point above thev upperxplate exclusively. l 3. an absorption tower or the like, the combination of a plurality of superposed 11o` buibbling floor embodying two 'vertically' LaoV i 1 perforated pairs of plates, the plates of each y pair enclosing between them a frothv cham-- bei', meansfor 'feeding gas under pressure to the lower side of the lower plate of a pair, and means for removing froth Yfrom above the upper plate of a pair and delivering the 'liquid from said froth directlyto the enclosed chamber between the next lower pair of plates.

4. In an absorption tower or the like, the combination of a plurality of superposed perforated pairs of plates, the plates of each pair enclosing between them a froth chamber, means for feeding gas under pressure to the lower side of the lower plate of a pair, and means for removing' froth from above the upper plate of a pair and delivering the liquid from said froth to the en-v closed chamber between the next lower pair of plates, said means comprising a pan mounted above the upper plate of the first mentioned pair, and a discharge tube leading from said pan through said pair of plates and extending downwardly and communicating with the enclosed chamber betweenthe next lower pair.

5. In an absorption tower or the like, the combination of a plurality of superposed perforated pairs of plates, the plates of each pair enclosing between them a froth chamber, means for feeding gas under pressure to thel lower side of the lower plate of a pair, and means for removing froth from above the upper plate of a pair and delivering the liquid from said froth to the enclosed chamber between the next lower pair of plates, said means comprising a pan mounted above the upper plate of the first mentioned pair, a discharge tube leading from said pan through said pair of plates and extending downwardly and communicating with the enclosed chamber between the next lower pair, and a spreader cone mounted on the lower plate of said next lower pair directly under the said discharge tube and spaced above said lower plate, said lower plate being provided with perforations under the spreader cone for the purposes described.

6. In an absorption tower or the like, the combination of suitable shell, a plurality of superposed spaced floors supported in said shell, each floor embodying a pair of spaced perforated plates enclosing a froth chamber, means to feed gas under pressure to the space under the lowermost floor, means to feed liquid to the space above the uppermost floor, and means to remove liquid from froth above the upper plate of each floor and to deliver said liquid through said iioor and into the enclosed froth chamber of the floor next below.

7. In an absorption tower or the like, the combination of a suitable shell, a plurality of Superposed spaced floors supported in said shell, each {'loor embodying a pair of spaced perforated plates enclosing a froth chamber, means to feed gas under pressure to the space under the lowermost floor, means to feed liquid to the space abovethe uppermost floor, and means to remove liquid from froth above the upper plate of each floor and to deliver said liquid through said floor and into the enclosed froth chamber of the Hoor next below, said last mentioned means embodying froth overflow pans above the vupper plate of each floor, discharge tubes leading downwardly from the froth overflow pans and extending to and communicating with the enclosed froth chamber between the plates of the-Hoor next below, each lower plate of each floor having mounted thereon a cone spreader under each of said discharge tubes, said spreaders being spaced above said lower plates and the lower plates being perforated under said spreaders.

8. In an absorption tower or the like, a bubbling fioor embodying a plurality of vertically spaced perforated plates enclosing between them froth chambers, means for feeding liquid directly into the chamber above the lowermost plate, means for supplying gas under pressure under the lowermost plate, and means for removing froth from a point above the uppermost plate.

9. In an absorption tower or the like, the combination of a plurality of series of spaced superposed perforated plates, the plates of each series enclosing between them froth chambers, meansfor feeding gas under pressure under the lowermost plate of a series, and means for removing-froth from above the uppermost plate of a series and delivering the liquid from said froth directly to one of the. froth chambers between the plates of the next lower series. y

10. In an absorption tower or the like, the combination of a suitable shell, a plurality of superposed spaced floors supported in said shell, each floor embodying a plurality of spaced perforated plates enclosing froth chambers, means to feed gas under pressure to the space under the lowermost floor, means to feed liquid to the space above the uppermost floor, and means to remove liquid from froth above the uppermost plate of each floor and to deliver said liquid through said floor and into one of the froth chambers of the floor next below.

In witness that I claim the foregoing I have hereunto subscribed my name this 9th day of July, 1926.

JULIAN A. CAMPBELL. 

